Structural Performance of Glued Laminated Bamboo Beams

Abstract

This paper presents a study aimed to characterize the structural performance of laminated bamboo lumber (LBL) and bamboo glulam beams (BGBs) as a first step to evaluate their potential application as a structural material. LBL was tested to determine their flexural, tensile, and shear properties, whereas BGBs were tested for their flexural, shear, and compressive properties. The BGBs were fabricated using two different adhesives: isocyanate resin (ISO) and phenol-resorcinol formaldehyde (PRF). BGBs with ISO performed better in bending strength, whereas the stiffness of glulams with both glue types was equivalent. Irrespective of the glue type, failure modes and shear test data showed BGB bending strength was limited by interlaminar shear in the LBL used in BGB fabrication. From the experimental study, it is concluded that the LBL does possess higher allowable and average strength values in tension and bending and comparable stiffness values, with much less variability to a commonly used structural species of wood, Douglas fir. The potential of using LBL in framing applications exists. However, certain impediments need to be addressed and researched before acceptance of LBL and BGB in the construction marketplace.